1999 mercury 90elpho trim motor question

[mikeneal]

I have a bad trim pump motor on my '99 mercury 90 elpo and was wondering if I can remove just the motor or does the entire assembly have to get removed?

 

[mikeneal]

Re: 1999 mercury 90elpho trim motor question

Worked on the boat tonight, removed the two long screws that attached the motor to the reservoir. I could do that without removing entire assembly. Can I just replace the motor and therefore forgo removing the base. ( pins are stuck in the transom bracket so the back screws of the flange are hidden)

 

[RRitt]

Re: 1999 mercury 90elpho trim motor question

Worked on the boat tonight, removed the two long screws that attached the motor to the reservoir. I could do that without removing entire assembly. Can I just replace the motor and therefore forgo removing the base. ( pins are stuck in the transom bracket so the back screws of the flange are hidden)

the reservoir is part of the motor. you have to remove the whole thing. you should never split the motor by removing two top bolts. If you do split the motor then it needs new seals. The seals are not reuseable as they often conform to imperfections during install and the motor requires an absolutely waterproof seal.

you may be able to replace the motor by removing upper pin and swinging trim assy forward. Usually, salt water boats are so hard to work on that you should plan on a few days of very frustrating work.

 

[mikeneal]

Re: 1999 mercury 90elpho trim motor question

Not being difficult rrit, i appracate everyones advice. I got a factory manual and it has the order of assembly listed as reservoir to pump base and then motor to the reservoir. I understand there are o-rings in place and the sealing surfaces must be clean/ defect free but shouldn't it be acceptable to replace just the motor? No doubting, just asking.

 

[dave 416]

Re: 1999 mercury 90elpho trim motor question

I had trouble with a trim motor from that vintage it would run and stop sporadically turned out the thermal override was dirty cleaned it up problem solved

 

[RRitt]

Re: 1999 mercury 90elpho trim motor question

Not being difficult rrit, i appracate everyones advice. I got a factory manual and it has the order of assembly listed as reservoir to pump base and then motor to the reservoir. I understand there are o-rings in place and the sealing surfaces must be clean/ defect free but shouldn't it be acceptable to replace just the motor? No doubting, just asking.

if you have three ram system then motor and reservoir are separate parts.

I assumed you had the single ram from your mention of top bolts. With single ram systems, the reservoir is part of the motor. It houses both lower bearing and lower oil seal while also providing the seat for armature end-play. In general, splitting the motor open on a single ram is the kiss of death. The most common mistakes being cracked brushes and re-used housing seals.

 

[mikeneal]

Re: 1999 mercury 90elpho trim motor question

After a week of pb blaster soaking I got the top pin to move and then I could rotate the pump out and get the back hardware. New pump and reservoir is on the way and I won't spilt them up. Thanks everyone for the help. Silly question, can I fill / purge in place?